I was also a participant in Hengel's Famous Friday
Night Table Talks (for 5 years, 1990-1995), but I
don't recall his ever discussing this point (though he
might have done so before my German improved enough to
follow the discussion).
I also don't recall Hengel's specific reasons from my
reading of his book some 10 years ago, but I think,
though, that Hengel draws his conclusions--that the
title belongs to the text of the Fourth Gospel and
that the author of chapter 21 added it--from his
arguments that John the Elder was the author of the
first 20 chapters and that the earliest references to
the Fourth Gospel refer to it as "The Gospel According
In other words, Hengel's argument is probably based
upon his narrowing of the historical window to a brief
enough time (between the probable date of John the
Elder's death and the first reference to the Gospel of
John) that the most plausible conslusion is that the
author of chapter 21 added the title.
Hengel probably has other reasons as well, but as I
said, I don't recall them. Wish that I could be of
more help on this.
Perhaps I'll ask him the next time that we correspond.
Do You Yahoo!?
Talk to your friends online with Yahoo! Messenger.